32
350
30
300
Via le Eggs ( , )
Temperature (°C)
28
250
26 24
200
22
150
20 18 16
Temperature Target Temperature
14 12 June 2004
100
Viable Egg Production
Oct. 2004
Feb. 2005
Months
June 2005
50 0
Oct. 2005
Figure . Spawning duration and egg production of captive red porgy in 2005.
Between January 28 and March 3, the survival and growth of larval red porgy from egg through the metamorphic stages were studied under pilot-scale hatchery conditions. The larval-rearing system consisted of three black 155-l cylindrical tanks, each supplied with 1-µ-filtered flow-through full-strength seawater at an exchange rate of 2.5 times/day. Constant light intensity was maintained at the water surface with 18 hours of daily light. The temperature was kept at 22°C. Nannochloropsis oculata algae was added twice daily to maintain a density of 300,000 cells/ml from one day posthatch until the end of the rotifer feeding period. Three days posthatch, enriched Brachionus rotundiformis rotifers were added to each rearing tank at a density of 6 rotifers/ml. Once feeding commenced, rotifer density was increased to 20/ml. The larvae also received artificial microdiets. Newly hatched Artemia nauplii were introduced at a rate of 0.25/ml 12 days posthatch, and by 17 days, larvae were fed enriched Artemia at a density of 1.2/ml. By day 26, the larvae were completely weaned to artificial dry diets. Larval survival to day 10 posthatch was 75.0 ± 2.2%. At this time, swim bladder overinflation contributed to a significant
Juvenile red porgy in a pilot-scale recirculating system at the University of North Carolina Wilmington.
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